1. Field of the Invention
The present invention relates to a resin-sealed semiconductor device downsized in a planar direction and a method for manufacturing the resin-sealed semiconductor device. Additionally, this invention relates to a substrate used for forming the resin-sealed semiconductor device and a method for manufacturing the substrate.
2. Background Art
A conventional resin-sealed semiconductor device includes, as shown in FIG. 7(d), a plurality of terminal portions 70, each having an internal terminal face 70a and an external terminal face 70b respectively formed on front and rear faces thereof, a semiconductor element 50 located on a die pad 75, wires 30, each connecting the internal terminal face 70a of each terminal portion 70 with the semiconductor element 50, and a resin sealing portion 40 made of a resin material for sealing the terminal portions 70, die pad 75, semiconductor element 50 and wires 30, such that a part of the external terminal face 70b of each terminal portion 70 can be exposed to the outside (see JP1984-208756A (TOKUKAI-SHO No. 59-208756), JP2002-289739A and JP2002-16181A).
In addition, a projection (or projections) 70t is provided to the periphery of the internal terminal face 70a (or top face) of each terminal portion 70, in order to prevent unwanted peeling between the resin sealing portion 40 and the terminal portions 70, occurrence of cracks in the terminal portions 70 and the like, due to force exerted on these portions when a base plate 1 is peeled off from the semiconductor device, as will be described later (see FIGS. 7(a) through 7(d)). Furthermore, as shown in FIGS. 7(a) through 7(d), a projection (or projections) 75t is also provided to the periphery of a top face of the die pad 75 (see JP2002-289739A).
The resin-sealed semiconductor device of this type is manufactured in the following manner. First, the base plate 1 is prepared (see FIG. 7(a)). Then, a front face of the base plate 1 is plated, so as to form the plurality of terminal portions 70, each having the internal terminal face 70a and external terminal face 70b respectively provided on the front and rear faces thereof, together with the die pad 75 (see FIG. 7(a)). Simultaneously, the projection 70t is formed around the periphery of the internal terminal face 70a of each terminal portion 70, while the projection 75t is formed around the periphery of the top face of the die pad 75.
Thereafter, the semiconductor element 50 is mounted on the die pad 75, and is then electrically connected with the internal terminal face 70a of each terminal portion via the wire 30 (see FIG. 7(b)). Subsequently, the terminal portions 70, die pad 75, semiconductor element 50 and wires 30 are sealed with the resin sealing portion 40 made of the resin material (see FIG. 7(c)). Finally, the base plate 1 is removed from the semiconductor device, so as to expose the external terminal face 70b of each terminal portion 70 to the outside (see FIG. 7(d)).
Because such a finally obtained resin-sealed semiconductor device has no base plate 1, the thickness of the semiconductor device can be substantially reduced. However, since each terminal portion 70 has the internal terminal face 70a and external terminal face 70b respectively provided on the front and rear faces thereof, such a terminal portion 70 should be arranged outside the periphery of the die pad 75. Thus, only the device of the so-called Fan-Out type can be manufactured. Accordingly, there is still a need for sufficiently or significantly downsizing the resin-sealed semiconductor device in the planar direction (or any suitable direction vertical to the thickness direction of the device).